The British Journal of Radiology, Vol 69, Issue 827 1045-1048, Copyright © 1996 by British Institute of Radiology

ARTICLES

Short communication: The absolute signal-to-noise ratio in MRI acceptance testing

DW McRobbie
Radiological Sciences Unit, Hammersmith Hospitals NHS Trust, Charing Cross Hospital, London, UK.

The absolute signal-to-noise ratio (SNR) measurable from images is defined and related to the theoretical fundamental SNR for MRI. Absolute SNR for quadrature head coils was obtained by both measurement and analysis of published data for MRI systems in the range 0.5-1.5 T. Mean absolute SNR for 22 MRI systems was 1.59 +/- 0.25 x 10(4) Hz1/2 ml-1 T-1 and did not vary significantly with the static field strength or gradient strength and signal bandwidth. This can be related to the fundamental SNR calculated as 2.36 x 10(4) Hz1/2 ml-1 T-1 through an effective noise figure with an average value of 3.4 dB for the 22 systems. Use of this methodology is discussed in relation to acceptance testing and performance assessment.

This article has been cited by other articles:

				D W McRobbie and R A Quest Effectiveness and relevance of MR acceptance testing: results of an 8 year audit Br. J. Radiol., June 1, 2002; 75(894): 523 - 531. [Abstract] [Full Text] [PDF]